The present invention relates to solid waste material sorting and recycling systems. More particularly, the present invention relates to a method of producing a reusable fuel substance by separating materials in a salvage operation which receives mixed materials, such as automobiles.
Since millions of automobiles become old or unusable, automobile disposal creates an enormous problem. The scrap metal industry has attempted to alleviate this problem by designing several types of mechanized recycling systems.
At these recycling centers, complete automobile bodies (including the seats and upholstery) as well as other types of metallic (containing various amounts of contamination and non-metallic components) are shredded into smaller pieces. The goal is to separate the metallics from the non-metallic components. While the metallics are typically recycled, the non-metallic materials have traditionally been taken to a dump for disposal. This has primarily been due to industry""s inability to find an effective, cost-effective alternative.
In an effort to extend the life of existing landfill facilities and as space in them becomes more limited, there is renewed interest in exploring new alternatives. This is heightened by the trend in automobile design toward fewer and fewer metallic components and an increasing the number of non-metallic components. Therefore, it is necessary to develop systems for sorting and recycling as many reusable automobile components as possible. Specifically, there remains a need for improved methods whereby non-metallic materials are converted into reusable byproducts.
The present invention provides a method for recovering a fuel substance by separating materials in a recycling operation based on BTU content.
In the present method, a non-sorted material stream including metallic and non-metallic components, which may include automobile scrap, is fed to a shredder which fragments the materials. After shredding, the non-sorted material stream is separated by a series of separators.
The non-sorted material stream is first conveyed to a gravity separator where the materials are separated into two streams, namely, a heavy material stream and a light material stream. The heavy material stream is then conveyed to a magnetic separator where ferrous metals are separated from a number of non-ferrous materials. The heavy ferrous metals are collected for recycling whereas the heavy non-ferrous materials are conveyed to a trommel screen and further separated into non-ferrous metal and non-metallic material. Both products are subsequently recycled after sizing.
The light material stream is passed under a cross belt magnetic separator where the light ferrous metals are separated out. The remaining light material stream is then conveyed to a rotary trommel which separates the light material stream into two fractions based on size. The fine material separated by the trommel has been rendered relatively inert. The larger material from the trommel is further separated to remove non-ferrous metal material. The remaining coarse material has a high BTU content, and can be utilized as fuel substance.